Method of producing hollow glass bodies.



N0. 703,6]8. I Patented July I, I902.

- P. T. SIEVERT.

METHOD OF PRODUCING HOLLOW GLASS BODIES.

(Appiication filed Mar. 91, 1902.)

2 Sheets-Sheet- (No Model.)

ml.- NORRIS FETIRS eb. PnOTuu'ma. WASHINGTON. D4 0.

No. 7os,s|a. Patented July I, I902.

P. T. SIEVERT. METHOD OF PRODUCING HOLLOW GLASS BODIES.

(Application filed Mar. 91, 1902.)

2 Suits-Sheet 2.

(mi Mddel.)

Wain 6019862- UNITE STATES- PATENT I OFFICE.

PAUL THEODOR SIEVER'I, or DRESDEN, GERMANY.

METHOD OF PRODUCING HOLLOW GLASS BODIES.

SPECIFICATION forming part Of Letters Patent N0, 703,618,dated July 1,1902. Application filed March 21, 1902. $erial No. 99,323. (Nospecimenal T0 aZZ whont it may concern.-

Be it known that I, PAUL THEODOR SIE VERT, a subject of the King ofSaxony, and a resident of Dresden, in the Kingdom of Saxand usefulImprovement in the Methods of Producing Hollow Glass Bodies, of whichthe following is a specification.

In the manufacture of hollow glass bodies it is generally essential thatbesides giving the body the desired shape an equal-or uniformdistribution of the glass mass throughout all parts of the body shouldbe effectedthat is to say, that the wall or walls .and the bottom shallhave a uniform or, as nearly as possible, a uniform thickness. Thisuniformity is sometimes difficult to obtain.

In producing hollow glass bodies by the blowing process performedthrough the mouth-tube the equal distribution depends upon the skillofthe glass-blower, who by means of sagging, turning, and swinging and byrepeatedly reheatingthe glass distributes throughout the body the glasswhich naturally tends to accumulate at its bottom or bulged-out end. V

In producing hollow glass bodies by the blowing process mechanicallyperformed by an artificial elastic pressure medium this distributiondepends, mainly, upon the action of the elastic pressure medium,sometimes on such action assistedby the sagging of the glass by its ownweight; but that method of distributing accumulations in the glass massis far from being satisfactory. 1

The present improvement is applicable in connection either. with themouth-blowing process, or with the mechanicallyrperformed blowingprocess, or with the process of forming hollow bodies by allowing-aplastic layer or mass of glass to sag. by its own weight while supportedat its edges; and the object of said improvement is to counteract orovercome the natural tendency'hereinbefore mentioned to accumulation ofthe glass at the bottom or bulged-out end of the hollow body and toeffect the distribution of such accumulations through other parts ofsaid body. In the mouth-blowin g process this improvement will allow theworking with a more highly heated mass of glass than heretofore and thenew method generally will enable bodies of very great size to beproduced without reheating-that is to say, in one heateither by ,blowingor by permitting the simple sagging ony, German Empire, have invented anew of the mass of glass in the open air or in molds, or by sagging andby blowing combined.

For the purposeof such distribution of glass, as hereinbefore mentioned,in the production of hollow glass bodies by the processes hereinbeforereferred to my invention consists, essentially, in forming a temporaryindentation into the bottom or bulged-out end or portion of the glassmass, layer, or blank which is under operation, at which bottom,

end, or portion, as is well known, the greatest accumulation of glasstakes place. Such indentation will cause a. distribution of theaccumulated glass into the walls of such indentation or in a lateraldirection. This temporaryindentation may be made by allow- .ing themass, layer, or blank to settle on a properly-shaped core, upon whichthe plastic glass in its accumulated thickness shapes itself, and thusdistributes said accumulation of the glass. When this indentation hastaken place, the mass, layer, or blank is lifted from said core, whenthe indentation which has been thus created will afterward bulgeoutdownwardly, and the mass, layer, or blank being-thus again roundedoff at its lower portion is or may be either in the open air or in amold'further treated by simply allowing it to sag by its own weight orby so allowing it to sag and at the same time blowing it out as to causeor permit it to attain the desired final shape. This final shaping ofthe mass or blank'may, however, also be efiected while the said mass-orblank still rests on the said core .by drawing upward the tool orimplement to whichthe said mass or blank is attached forsagging, or forboth sagging and blowing, or the saidshaping may be effected while saidtool orimplement rests stationary by lowering the core, or it maybe'effected by drawing upward said tool or implement whilesimultaneously the said core is lowered. In all these cases the plasticmass of glass finds its support upon the indenting-core, and by theremoval or distribution of the exthe mass or blankby means of the saidcore a uniform distribution of the mass of glass into the bottom or intothe sides of the body to be formed is caused.

Figures 1 to 13 are vertical sectional views, which will be hereinafterdescribed in detail in their regular order, illustrating the process asperformed by the mouth-blowing, by the mechanical blowing, and by theblowing and sagging operation combined. Figs. 14, 15, 16 are plan viewsof cores of different forms for producing the indentation in the glassmass, layer, or blank. Figs. 17 and 18 are vertical sectional viewsillustrating two stages of the operation performed by the blank showninFig. 16; Fig. 19, avertical sectional view at right angles to Fig. 18.

In Figs. 1, 2, 3, if represents the glassblowers mouth-tube. In Fig. 1 amass of molten glass it is shown as picked up on the said tube andpartlyblown out in bulb form. Fig. 2 illustrates the further blowing outof a bulb while it is supported at its bottom or most protuberantbulged-out portion on a core I) of conical form, by which there isformed into it an indentation, and there is produced a stretching of thebottom which increases its area and causes a uniform or nearly uniformdistribution of the plastic mass of the glass and uniform or nearlyuniform thickness of the bottom and sides of the hollow body produced bythe blowing. Fig. 3 represents the blown-out hollow body after theremoval or withdrawal of the core I) and after the sagging down andbulging out of the portion of the body which has been stretched by theindentation produced by the core. After the body has arrived, asdescribed, in the condition illustrated by Fig. 3 a final shaping of thebody may be produced by a further sagging of the glass by its own weightor by blowing, or by both sagging or blowing, with or without theassistance of a mold.

In Figs. 4 to 7the method of using a core I) for the purpose of thisinvention is illustrated in connection with the known process of forminga hollow glass body beginning with formingalayerof liquid glass e. WVhenthe spreading of such layer upon a plate cl has taken place and a frame0 has been applied and pressed into the liquid or plastic mass, as shownin Fig. 4, so as to take hold of it, and the frame and the glass havebeen turned upside down, the glass resting upon said frame 0 will beginto sag within the latter, as shown in Fig. 5, and an accumulation ofglass will take place in the bottom of the layer or blank. The saidbottom is then caused to rest upon the core I), properly placed, asshown in Fig. 6, in relation to said frame 0, so that an indentation orbulging in of the accumulation of glass is formed, the formation of suchindentation causing a distribution of the accumulated glass into thewalls of the indentation. After removing the piece or blank from thecore or removing the core from the blank or piece the final shaping ofthe hollow glass body may be performed either by sagging or blowing inthe open air or into a mold 711., as shown in Fig. 7, in which is alsoshown in dotted lines a pipep for the admission of an elastic pressuremedium. In all these cases the indentation caused by the core willafterward bulge out and the hollow glass body will shape with a bottomof a thickness in correspondence with the thickness of the walls.

The method as illustrated in Figs. 8 to 13 starts from the same initialformation of the hollow glass body by forming a flat layer of liquidglass and after the commencement of the formation of the piece or blankusing a core I) for distributing the glass accumulation at the bottom.The first proceeding with this core in Fig. 8 corresponds to thatillustrated in Fig. 6, with this modification: that the tool orimplement which holds the piece or blank for the hollow body is made tobe lifted up or elevated, so that while the core I) continues to be incontact with the glass bottom the hollow body is formed by being drawnin an upward direction.

According to Figs. 11 to 13 the method is intended to be carried out sothat the tool or implement holding the piece or blank remains stationarywhile the core I) is lowered down, thus causing the formation of thebody by drawing the piece or blank in a downward direction. These twoprocedures-that is to say, the removal of the piece or blank in upwarddirection, according to Figs. 8 to 10, and the removal of the core indownward direction, according to Figs. 11 to 13-may be combined fordrawing the piece or blank and distributing at the same time theaccumulation of glass at the bottom, the indentation at the bottom beingallowed to bulge out after removal of the core.

Of the several forms of the core b shown in Figs. 14, 15, 16 which maybe used, Fig. 14 is conical, Fig. 15 is pyramidal, and Fig. 16cylindrical. Said core may, however, be of any desired shape or form.

In Figs. 17 to 19 the new method of distributing the glass at the bottomof the piece or blank is shown with the use of a core I) of cylindricalshape according to Fig. 16. Such a core will prove to be very useful forthe method of distributing glass in the manufacture of hollow glassbodies of considerable sizesuch, for instance, of glass bath-tubs. Afterthe layer of glass 0, carried by frame 0, has been broughtinto positionand condition, as illustrated in Fig. 17, the core I) is brought intothe position illustrated and is rolled or moved to and fro below theglass layer, which is supported by said core, in order to cause theuniform distribution of the glass accumu lation while the piece or blankis continuously sagging. After removal of said core the piece or blankis subjected to the final blowing operation' in a mold, therebyreceiving a thickness of the bottom corresponding to the thickness ofthe walls.

WhatI claim as my invention is- 1. The herein-described improvement inthe process of producing hollow glass bodies, which consists in firstobtaining a partlyformedhollow body from a mass of liquid glass andafterward while said'body remains plastic distributing an undesirableaccumulation of glass which may occur in any part part thereof from itsexterior and allowing the glass while still plastic to sag at thesidesof such indentation, and finally allowing the said indentation to bulgeoutward. V

3. The herein-described improvement in the process of producing'hollowglass bodies, which consists in first obtaining a partly formed hollowbody from amass of liquid glass, next for the purpose of distributingsuch undesirable accumulation of glass as may occur in any part of saidpartly-formed body, producing an indentation into such part thereof fromits exterior and at the same time blowing said body from its interior,and finally bulging out the so-indented part by continued blowing.

In testimony that I claim the foregoing as my invention'I have signed myname',in presonce of two witnesses, this 8th day of March,

PAUL THEODOR SIEVERT,

Witnesses:

HERNANDO DE Soro, PAUL AREAS.

